It's all about insulin and carbohydrates... with a side side of incestous and tenuous public health science.

Interview with Gary Taubes, author of Good Calories, Bad Calories: Fats, Carbs, and the Controversial Science of Diet and Health. Much more at the link.

TMUSCLE.com | Eat Your Lungs Out While Getting Leaner:

"...some of my physicist friends said to me, "If you like writing about bad science, you should check out public health. You'll have a field day."

So I started writing about public health, and it turns out the science was pretty universally terrible. I did a story for Science magazine, in which I spent a year on the controversy over whether dietary salt causes high blood pressure. One of the worst scientists I ever interviewed — and I had interviewed some really terrible scientists in my life — took credit for getting Americans not only to eat less salt, but also to eat less fat and less eggs.

I literally put the phone down when I was done with the interview, called up my editor, and said one of the five worst scientists I've ever interviewed took credit for getting Americans to eat less fat and less eggs. I don't know what the story is with fat and eggs, but if this guy was involved in any substantive way, then there's a good story.

After I finished the salt story, I spent a year reporting a story on how we came to believe that low-fat diets are good for us. Again, the science behind it was pretty universally terrible. And that led me to do The New York Times Magazine story.

They wanted me to do a story for the magazine where we try to figure out what caused the obesity epidemic, because you could localize it in time. Basically, some time from the late 1970s to the early 1980s, obesity in America started shooting upward.

There were two hypotheses. One said high-fructose corn syrup was to blame, but that didn't really pan out. Its bad stuff, but it's not the cause of the epidemic.

But this other idea, that the low-fat doctrine was to blame, was interesting because I came upon these five studies that had been done, but not yet published, on the Atkins Diet. They put people on a high-fat Atkins Diet, and compared them to people put on a low-fat, low-calorie, American Heart Association-type diet. And not only did the people on the Atkins diet lose more weight — even though you're not telling them to eat less — they also had better cholesterol profiles.

...It makes absolutely no sense that your fat tissue wouldn't be regulated, and yet these people believe that obesity is all about calories.

...The argument I'm making is that [obesity is] a disorder of excess fat accumulation, not of sloth and gluttony. Overeating is the side effect of the disorder, not the cause. What you want to know is, what regulates fat accumulation?

...The answer, which we've known since the early 1960's, is insulin. Insulin is the hormone that primarily regulates fat accumulation. If you want to get fat out of your fat tissue, you have to lower your insulin levels.

And insulin is regulated for all intents and purposes by the carbohydrates in our diet. That's the simplest possible hypothesis. The physicist would call it "the zero-order approximation."

Other hormones play roles, and most of them work to get fat out of the fat tissue, but they can't do it if insulin levels are elevated. Adrenaline, growth hormones, all these things work to make you leaner, but they don't work if insulin levels are elevated.

And this has never been controversial. That's the weird thing.

TM: That's never been controversial?

GT: No.

TM: That carbohydrates make you fat?

GT: Well, that insulin makes you accumulate fat, and that carbohydrates regulate insulin levels.

TM: People don't just put those two ideas together?

GT: Nobody puts them together because they don't like the conclusions.

Everything that we believe about obesity basically came out of the 1970's. This was a period in which a half a dozen men completely dominated the field. So they controlled what everybody was allowed to think.

They wrote all the textbooks. Every textbook on obesity that isn't about behavioral therapy was written by one of these six men. Well, actually only two guys wrote the textbooks, which were often accumulations of chapters written by different people. So they would invite one of these other six to write the relevant chapters.

In a textbook on obesity, you'd have a chapter on dietary therapy. That chapter would always be written by the same guy: Ted Van Itallie. A very nice guy. I've interviewed him. What he believed became what everyone believed. As these guys started to retire, in the 1980's, their protégés took over.

These guys would also host the conferences, and then they would write up the conference proceedings. So they would take what was presented in the conference and they would filter it into what they believed was true..."